Retaining nuts are used to secure devices, for example a hub, upon a spindle. Typically both the spindle and nut are threaded. Devices are secured upon the spindle before the nut is screwed onto the spindle, the nut abutting the exterior side of the device. Vibration, associated with the rotation of the spindle, may cause the nut to unscrew and disengage from the spindle. The device is no longer secured and may detach itself from the spindle.
Numerous devices have been used to secure the nut to the spindle. Simple versions of these devices include lock washers, jam nuts, self-locking nuts and slotted nuts used in conjunction with a cotter pin. More advanced versions of securing devices include the controlled axle nut system of U.S. Pat. No. 5,795,037 to Hagelthorn and the nut and bolt locking system of U.S. Pat. No. 5,967,723 to Duran. Hagelthorn provides a retainer member which must be threaded onto the spindle. The threading process can be difficult, especially in cases where the parts are being assembled by machine. Potential assembly difficulties are cross-threading and the need to protect the internal threads of the retainer from damage. Duran provides a nut and washer locking combination where the washer deforms to form an interference fit with flats on the face of the nut as the nut is tightened upon a bolt. Locking contact between the nut and washer occurs only at one end of the nut.
A system which can be easily assembled and which provides a strong locking connection between the spindle nut and the nut retainer is desired.